Core taking apparatus



Dec. 26, 1939. G. G. HARRINGTON CORE TAKING APPARATUS Filed Aug. 27, 1937 r 6 VJ, V 0 7w V/ 3 W W PatentedDec. 26, 1939 UNITED STATES CORE TAKING APPARATUS George G. Harrington, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a

corporation of Texas Application August 27, 1937, Serial No. 161,185

7 Claims.

This invention relates in general to sample taking devices, and more particularly to a device for taking cores from the formation at the bottom of a well being drilled. The invention relates especially to an arrangement whereby the drilling fluid may be prevented from flowing through the space adapted to receive the core and whereby the same may be kept substantially free from cuttings and other debris during the 10 time it is being lowered into the well, and to a means for protecting the clogging of the coreretaining means by the drilling fluid and debris therein.

In the past various arrangements have been devised for receiving cores cut from the formation at the bottom of a well being drilled, and for removing such cores to the surface of the ground so that information regarding the nature of the formation may be obtained. Such devices have for the most part, however, been open at both ends during the time that they were being lowered into the well, so that mud or other liquid in the well would pass into and up through the core barrel as it was being lowered. This naturally caused a considerable accumulation within the core barrel of cuttings or other debris which might be suspended by the liquid in the well.

It is, therefore, an object of this invention to provide a sample taking device including va core barrel which may be lowered into a well without theflow therethrough of the liquid contained in the well, and consequently without the accumulation therein of cuttings and other debris which might be suspended in such liquid.

It is a further objectto provide a device of the character set forth in which the core barrel may be lowered to core taking position without taking in matter which might contaminate or afiect the value of the core to be taken. It is a further object to provide a means for retaining a core within a core barrel, and provide an ar- Y rangement whereby such means will be held in inactive position and protected against clogging by the drilling fluid and debris therein until the core is to be taken.

It is a further object to providea device of the character set forth in which the upper end of the core barrel will be normally closed during the time it is being lowered into a well, but which may be then opened to permit upward flow through the core barrel during the taking of a core.

this invention contemplates the various parts and With the foregoing and other objects in view,

combinations set forth in the accompanying drawing, and in the following description, it being understood, however, that said drawing and description are by way of illustration and example only, and are not to be taken as in any way 5 a limitation upon the scope of this invention.

Referring now to the drawing in which like numerals indicate corresponding parts throughout:

Fig. 1 is a view partly in vertical cross section 10 illustrating the lower end of a core barrel constructed in accordance with this invention in place within a core bit.

Fig. 2 is a viewin vertical cross section illustrating a continuation of the upper portion of 15 the structure shown in Fig. 1.

Fig. 3 is a horizontal cross section taken along "the line 3--3 of Fig. 1.

In connection with this invention there is employed a core bit having a head I and outer and inner roller cutters 2 and 3 which together cut an annular opening and form a cylindrical core of the desired diameter. The head I is provided with passageways 4 and 5 located in its walls for the purpose of conveying washing 25 fluid to the cutters 2 and 3 just referred to. The bit is internally threaded at its upper end at 6 to receive the fitting 1, this fitting being likewise internally threaded at its upper end to receive the drill collar 8. The joint between the member l and the drill collar 8 is preferably welded so as to in effect combine these members into one integral structure.

Within the drill collar 8 is located the core barrel 9 upon the lower end of which is mounted a fitting l0, having an external downwardly facing shoulder ll, adapted to seat upon the 'upwardly facing shoulder or seat l2 in the core bit head. Extending laterally from the outer surface of the fitting Ill at a point just below the lower end of the fitting! there are provided a plurality of lugs [3 which cooperate with the lower end of the fitting I toseal the core barrel in proper position within the bit head and drill 45 collar. Extending laterally also from'the fitting 7 l0 will be found a, plurality of splines or ribs M, the outer edges of which lie closely adjacent the inner wall of the fitting I and serve as guidesfor the core barrelto. centrally locate the same with respect to thefitting 1. Adjacent the upper end of the core barre1'9 there are-located addiv tional laterally extending splines or ribs I5, the outer surfaces of which lie closelyadjacentthe inner surfaces of the drillcollar 8 so as-to serve as guides and centrally locate the core barrel within the drill collar.

The lower end of the fitting I0 is formed with a slightly enlarged internal diameter, and the interior of the bit is formed with an upwardly facing shoulder for the purpose of receiving the support l6 which carries core catcher elements l1 pivoted thereto at l8, and the core catcher. elements l9 pivoted thereto at 20. The core catcher elements l1 are relatively short and are spring-pressed inwardly and downwardly by means of leaf springs 2| carried by the support or collar IS. The elements I9 are relatively longer and are likewise spring-pressed inwardly and downwardly by means of a leaf spring 22 carried by the collaror support 16.

Positioned within the lower end of the core barrel and between the core catcher elements l1 and I9 is a sleeve-like member 23 adapted to protect the core catcher elements from the drilling fluid as the core barrel is being lowered into the well, and to prevent these elements from becoming clogged with such fluid and the debris carried thereby. This sleeve 23 is provided with notches or downwardly facing shoulders 24 and 25 for the purpose of receiving respectively the short core catcher elements 11 and the long core catcher elements I9. The downward movement of the sleeve within the core barrel is thus definitely prevented by virtue of the contact of these core catcher elements with the notches in the exterior surface of the sleeve. I

Below the core catcher elements the sleeve is formed with slits 26 atspaced intervals about its circumference, these slits extending longitudinally of the sleeve and forming between them portions which may be sprung or moved radially inwardly. On the exterior surface of each of these portions there is formed an outwardly projecting lug 21 having an inclined upper surface 28 adapted to frictionally engage the lower edge portion of the bit head and yieldably resist upward movement of the sleeve 23 with respect to the bit head when the parts occupy the position illustrated in Fig. 1, so as to prevent accidental displacement during lowering of the same into the W811.

The sleeve 23 is also formed with flattened sides or surfaces 29 at intervals "about its circumference so as to accommodate for the lower and inner edge of the inner cutters 3 on the core bit. The lower end 30 of the sleeve 23 extends a substantial distance below the cutters on the core bit so that when the drill is lowered into the well with the core barrel and the sleeve in place therein as illustrated in Fig. l, the lower end 30 of this sleeve will contact the bottom of the hole and cause the elements between the slits 26 to spring inwardly so that the lugs 21 will pass by the lower end of the bit head and permit the sleeve 23 to be forced upwardly into the core barrel.

It is to be noted that the upper end of the sleeve 23 is open as shown at 3|, and the lower end thereof is open as shown at 32, so that fluid is not prevented by the sleeve from passing into. or out of the core barrel.

Threaded into the upper end of the core barrel 9 is a valve fitting 33 having an opening therethrough. Intermediate its ends, this opening is interrupted by a partition 34 having smaller open ings 35 therethrough. At its lower end, a seat 36 is provided for a ball valve 31, this seat being held in position within the fitting 33 by means of a nut 33 or the like. Similarly at its upper end, the fitting 33 is provided with a seat member 33 ed to be actuated by a weight to be dropped in through the drill stem in the manner hereinafter described, and under the influence of such weight to move downwardly and unseat the ball valve 40 so that liquid may flow upwardly through the nut 38, past the valve 31, through the openings 35, and out through the openings 42 and 43. The valve 40 is resiliently urged at all times against its seat 39 by means of a coil spring 46 which bears against the upper surface of the partition 34 and carries the ball 40 on its upper end.

The drill collar 8 is externally threaded at its upper end to receive the lower end of a collar 41, this joint preferably being welded so as to integrally join these parts. The lower section of drill pipe 48 is threadedly connected to the upper end of the coupling 41.

In the operation of the device illustrated in the drawing, the coring apparatus is lowered into the well in the ordinary manner with the various parts in the position illustrated. While in this position, no flow can take place from the core barrel 9 through the upper end thereof because of the fact that the valve 40 is held seated against its seat 39 by means of the spring 48. Hence, if the core barrel 9 is initially filled with air or the like, as the hydraulic pressure 'in the well increases, this air will be compressed, and the drilling fluid in the well will rise in the core barrel accordingly. In the event that there is a slight leakage of air past the valve 40, the drilling fluid may rise until it entirely fills the core barrel. It is contemplated, however, that the core barrel may be initially filled with some other liquid than the drilling fluid employed, which liquid may be substantially incompressible and preferably lighter than the drilling fluid, so that as the core barrel is lowered into the well substantially no drilling fluid will enter the same, despite the fact that the lower end of the core barrel will be open through the sleeve 23. Since in neither instance will there be any flow of drilling fluid through the core barrel, there will not be the usual accumulation of cuttings, etc. within the core barrel, and the core which is subsequently taken will not be contaminated thereby.

When the bottom of the well has been reached, the lower end 30 of the sleeve 23 will contact with the bottom of the well and will be forced upwardly springing the lugs 21 radially inwardly so that they may pass the lower end of the bit and so that the sleeve may be forced upwardly into the core barrel. A weight is then dropped in through the drill stem to cause the plunger 44 to move downwardly and unseat the valve 40 after which fluid may pass upwardly from the-core barrel through the valves 31 and 40. The coring is then started, and as the core moves upwardly into the core barrel it pushes the sleeve member 23 upwardly and forces the drilling fluid or other liquid within the core barrel out past the valve 43. When the sleeve 23 has been moved upwardly'by the core a suflicient distance, the core catchers l! and I9 will be released, and when the coring operation is completed and the drill stem and apparatus attached thereto is raised, these core catcher elements will dig into the core and cause it to be lifted with the core barrel and retained in the core barrel while the core barrel is being drawn to the surface of the ground.

It will be understood that during the coring operation the core barrel may be allowed to rotate with respect to the core drill so that it will not rotate with respect to the core itself, but that this core barrel will be prevented from moving vertically in the core drill by means of the shoulder II and lugs l3.

It will be appreciated that any desired form of valve structure may be included at the top of the core barrel so long as such valve functions to accomplish the objects of this invention and falls within the scope of the appended claims.

It will be further appreciated that various changes and modifications may be made in the other parts illustrated and described without departing from the spirit and scope of this invention as defined in the following claims;

From the foregoing it will be appreciated that there has been set forth an apparatus capable of carrying out all the objects and advantages sought by this invention as hereinbefore set forth.

Having described my invention, I claim:

1. In a sample taking device, a core barrel having an opening adjacent the upper end thereof, a check valve for preventing downward flow through said opening, a second check valve carried by said barrel for preventing upward flow through said opening, a plunger for moving said second check valve to open position and having a part projecting upwardly beyond the upper end of said core barrel, and weight means adapted to be 40 dropped onto said plunger to move it and open yieldable in a radially inward direction, and

means projecting laterally from the exterior of said parts at a point intermediate their ends to engage a portion of a core bit and yieldably resist upward movement of the sleeve thereinto.

\ 3. As an article of manufacture, a sleeve-like member adapted to fit into the lower end of a core barrel, said member having longitudinal slits formed therein at a position spaced from the upper end thereof to form parts yieldable in a radially inward direction, and means projecting laterally from the exterior of said parts to engage a portion of a core bit and yieldably resist upward movement of the sleeve thereinto, said laterally projecting means having a beveled upper surface for engagement with the core bit whereby when said sleeve is forced upwardly said laterally projecting means will be forced inwardly to permit said sleeve to pass into the core barrel.

4. As an article of manufacture, a sleeve-like member adapted to fit into the lower end of a core barrel, said member having longitudinal slits formed therein at a position spaced from the upper end thereof to form parts yieldable in a radially inward direction, and meansprojecting laterally from the exterior of said parts to engage a portion of a core bit and yieldably resist upward movement of the sleeve thereinto, said sleeve hav- -ing portions of its outer surface cut away to accommodate the inner cutter of a core bit.

5. As an article of manufacture an elongated member adapted to fit into the lower end of a core barrel within a core bit, said member having, at a point intermediate its length, circumferentially spaced inwardly yieldable, laterally projecting parts adapted to engage a portion of the core bit and frictionally resist upward movement of said member relative thereto.

6. As an article of manufacture, a cylindrical member adapted to fit into the lower end of a core barrel within a core bit, said member having, at a point intermediate its length, laterally projecting parts yieldable radially inwardly and adapted to engage beneath a portion of the core bit, whereby said member is frictionally held against accidental upward displacement relative thereto.

7. As an article of manufacture, an elongated member adapted to fit into the lower end of a core barrel within a core bit, said member having an inwardly yieldable laterally projecting latching part adapted to engage beneath a portion of the core bit and yieldably latch said member against upward movement relative to said core bit.

GEORGE G. HARRINGTON. 

